Topic
Precision Time Protocol
About: Precision Time Protocol is a research topic. Over the lifetime, 604 publications have been published within this topic receiving 6006 citations. The topic is also known as: PTP & IEEE 1588.
Papers published on a yearly basis
Papers
More filters
TL;DR: This work proposes an enhanced synchronization algorithm to calculate the asymmetric ratio of the communication link, and the proposed algorithm enhances an accuracy of the time synchronization.
Abstract: IEEE 1588 is a standard to synchronize independent clocks running on separate nodes of a distributed measurement and control system. In IP based cellular network, it is considered as a key technology to synchronize base stations. Especially, interests for the low-cost and very-small home cellular base station called the Femtocell is increasing, and it is connected to the cellular core network using an asymmetric communication link such as xDSL. However, the conventional IEEE 1588 synchronization algorithm assumes symmetrical links, and makes errors for asymmetric links for the calculation of the time difference between the master clock (a clock source) and the slave clock (a clock consumer). We propose an enhanced synchronization algorithm to calculate the asymmetric ratio of the communication link, and the proposed algorithm enhances an accuracy of the time synchronization.
101 citations
21 Nov 2005
TL;DR: The design and implementation of two IEEE 1588 prototypes for wireless LAN (WLAN) are presented and the results achieved are fully comparable to those achieved with wired LAN implementations.
Abstract: IEEE 1588 is a standard for precise clock synchronization for networked measurement and control systems in LAN environment. This paper presents the design and implementation of two IEEE 1588 prototypes for wireless LAN (WLAN). The first one is implemented using a Linux PC platform and a standard IEEE 802.11 WLAN with modifications to the network device driver. The second prototype is implemented using an embedded WLAN development board that implements the synchronization functionality using an embedded processor with programmable logic device (PLD) circuits. The measured results show that 1.1 ns average clock offset can be reached on HW based implementation, while Linux PC network driver enables 660 ns with a standard WLAN. Although WLAN is an extremely difficult environment for the synchronization, the results achieved with the prototype are fully comparable to those achieved with wired LAN implementations
86 citations
01 Oct 2014
TL;DR: This document defines a set of security requirements for time protocols, focusing on the Precision time Protocol (PTP) and the Network Time Protocol (NTP), and discusses the security impacts of time protocol practices, the performance implications of external security practices on time protocols and the dependencies between other security services and time synchronization.
Abstract: As time and frequency distribution protocols are becoming increasingly
common and widely deployed, concern about their exposure to various
security threats is increasing. This document defines a set of
security requirements for time protocols, focusing on the Precision
Time Protocol (PTP) and the Network Time Protocol (NTP). This document
also discusses the security impacts of time protocol practices, the
performance implications of external security practices on time
protocols, and the dependencies between other security services and
time synchronization.
78 citations
TL;DR: The analytic formulas provide a theoretical ground for understanding the simulation results, some of which are presented, as well as the guidelines for choosing both system and control parameters.
Abstract: This paper analyzes the factors that affect the synchronization performance in peer-to-peer precision time protocol (PTP). We first study the influence of frequency drift in the absence of jitter and compare the gravity of the master drift with that of the slave drift. Then, we study the influence of jitter under the assumption of constant frequencies and the effect of averaging. The analytic formulas provide a theoretical ground for understanding the simulation results, some of which are presented, as well as the guidelines for choosing both system and control parameters.
72 citations
TL;DR: This paper proposes detection and mitigation mechanisms against the known PTP delay attack and applies model checking to quantify the effect of the delay attack, and results support the usefulness of the mechanism in detecting the delay attacks targeting PTP, and preserving the system functionality.
Abstract: Smart grid applications demand the availability of a reliable and accurate time signal. Measurements and events need to be correctly aligned to enable proper actions and decisions. Precision time protocol (PTP) is the favored protocol for time distribution across smart grid domains. The correct functionality of PTP is of paramount importance and its security is of high priority. To harden its security, detection, and prevention mechanisms against attacks targeting PTP are needed. In this paper, we propose detection and mitigation mechanisms against the known PTP delay attack. We apply model checking to quantify the effect of the delay attack. Moreover, the validity of the proposed mechanism is formally proven. The suggested approach is tested on a physical system. The collected results support the usefulness of the mechanism in detecting the delay attacks targeting PTP, and preserving the system functionality.
64 citations